Messages

301

General Mach Discussion / Re: BT30 spindle from scratch - with power drawbar and ATC of course

« on: September 21, 2012, 10:48:53 AM »

I considered a "remote" carousel and transfer arm, but it seemed to get too complex too quickly.

Agreed. However, the goal of unlimited tools eliminates a moving storage device as a possibility. Moving a carousel is easy enough, as you correctly point out, but moving a 6 or 7 (or more) foot long chain belt and associated drive mechanism would be impossible by any practical method that I can think of. Another consideration on this aspect is the cover s for the tool storage. Since the arm moves up and down, I think I can sidestep needing an opening access door . . . .  hopefully . .  maybe . . 

My current carousel design is really quite simple, with only two air cylinders for actuation, also fully inter-locked.

how are you sensing a successful tool change

By the carousel position.  The whole carousel drops down, moves under the spindle, then raises up to insert the tool.  If the tool does not correctly enter the spindle, the carousel will either hang up, and throw a fault, or the tool "fork" will break off, which will not be detected, but should be both VERY rare, and relatively harmless (I hope).

I'm using a Geneva driven by a simple gearmotor for tool selection.

Simple and effective for a carousel.  NG for the chain belt option, but a servo drive could be moved over with out much difficulty and the programming would not need to be significantly different . .  perhaps even handled by a config param.

Actually, no reason why a Geneva can't be used to move a belt just as well....

With luck, I should have it working in another week or so.

A week!  Jeez, It will take me a week to figure out how this new coffee maker works . . 

Well, I started on it a couple of months ago, but it's been on the shelf for a while.  I got the geneva, carousel disc, and all tool holders done and working - that all took just one day to machine.  I just have to make the mounting arm and housing.

302

General Mach Discussion / Re: BT30 spindle from scratch - with power drawbar and ATC of course

« on: September 21, 2012, 10:42:46 AM »

Heres a vid of the style on the Chiron.
http://www.youtube.com/watch?v=97KQ5DKSuNw
Hood

THAT is the single coolest toolchanger EVER!  :-)

Regards,
Ray L.

303

General Mach Discussion / Re: BT30 spindle from scratch - with power drawbar and ATC of course

« on: September 21, 2012, 10:21:20 AM »

Looking forward to seeing what you come up with!  I'm finally getting off my lazy a$$, and getting back on my ATC - a 10-tool carousel that will handle TTS initially, and, hopefully, eventually move to 30-taper.  I considered a "remote" carousel and transfer arm, but it seemed to get too complex too quickly.  My current carousel design is really quite simple, with only two air cylinders for actuation, also fully inter-locked.  I'm using a Geneva driven by a simple gearmotor for tool selection.  With luck, I should have it working in another week or so.

Regards,
Ray L.

304

General Mach Discussion / Re: How much stepper power do a 1-1/2 HP Bridgeport need to do a good job ?

« on: September 20, 2012, 06:22:36 PM »

The primary value of Micro-stepping is smoother operation, not necessarily higher precision.

305

General Mach Discussion / Re: How much stepper power do a 1-1/2 HP Bridgeport need to do a good job ?

« on: September 20, 2012, 01:36:49 PM »

If you have not found this site yet, you might take a look at
it. Bob offers great service and is always free to give you
advise. http://www.homeshopcnc.com/index.php?page=shop.browse&category_id=1&option=com_virtuemart&Itemid=9999

olf20 / Bob

Bob?  His name is Rick LaLonde.

Regards,
Ray L.

306

General Mach Discussion / Re: How much stepper power do a 1-1/2 HP Bridgeport need to do a good job ?

« on: September 19, 2012, 03:58:07 PM »

1600 oz-in should be more than adequate for a BP.  That won't be enough to move the knee without retaining the bevel gear drive, and adding another 4:1 or greater belt reducer.  But it should be quite adequate for X, Y and quill.

Regards,
Ray L.

307

General Mach Discussion / Re: burned a servo

« on: September 18, 2012, 07:31:30 PM »

i never got a manual, and i did look at gecko's site.... never found this info.

They're right there under "Support":

http://www.geckodrive.com/support/motor-control-manuals/dc-servo-drives/g320-rev-7.html
http://www.geckodrive.com/support/motor-control-manuals/dc-servo-drives/g320x-rev-10.html

308

General Mach Discussion / Re: burned a servo

« on: September 18, 2012, 07:01:36 PM »

Thank you! On phone 3 times with gecko... never once did they mention this.

I'll trouble shoot with this later tonight.

Have you not read the G320 manual??  It's all in there....

309

General Mach Discussion / Re: BT30 spindle from scratch - with power drawbar and ATC of course

« on: September 12, 2012, 02:59:56 PM »

Steve,

I guess that should be enough force.  :-)

So.....  I'm guessing you have a two-stack 4" cylinder, generating about 2500#, with a 1:2 cam arrangement pivoting on the shaft in the lower RH corner of the photo?

I'm curious why the release is so slow?  Is it a single-acting cylinder, and that's just the bleed-down time?

310

General Mach Discussion / Re: BT30 spindle from scratch - with power drawbar and ATC of course

« on: September 06, 2012, 01:22:06 PM »

Steve,

It's a thing of beauty!  A few things I'm not clear on:

Are the 4 Philips screws what retains the lower bearing?

What are the two "dimples" on the inner perimeter of the (assumed) bearing retainer?

Don't know if BT30 dogs are hardened, but it certainly would not hurt.  I wouldn't think it would be really necessary, however.  In theory, there should be no movement between the tool holder and spindle, and even if there is, it'll be once per tool, and the dogs will make contact, then should not move again until the tool is removed and re-installed.

Can't wait to see what you come up with for a PDB!

Regards,
Ray L.